Virginia is telling a federal appeals court it should rebuff a challenge from an agricultural powerhouse that challenges the U.S. Environmental Protection Agency's pollution diet for the Chesapeake Bay.

Largely in a response to an argument filed by 21 other states, Attorney General Mark Herring filed a friend of the court brief supporting the EPA and the standards it set for sediment and fertilizer chemicals in Chesapeake Bay waters. Dirt particles suspended in water blocks sunlight that underwater plants need to flourish. Nitrogen and phosphorus encourage algae, which suck oxygen from the water. Both cut fish, oyster and crab populations.

"States are far away as Utah, Montana, North Dakota and even Alaska weighed in ... to attack our plan," Herring said. "I will not go and leave unanswered the attacks of others on our plan to protect our waters.

The other states argue that the Bay cleanup plan is a first step towards a federal takeover of states' authority to regulate water pollution. They said they supported a challenge by the American Farm Bureau Federation that argues the plan is a federal over-reach into land-use regulation.

A federal district court judge in Harrisburg, Pa., rejected that argument, but the case is now before the 3rd U.S. Circuit Court of Appeals.

Herring is arguing that the Bay cleanup plan started with states in the Chesapeake watershed, and that the EPA's role has been to coordinate and keep the multi-state effort on track.

He noted that Virginia's participation in the latest effort came under former Gov. Bob McDonnell, while the brief argues that close cooperation between Virginia and Maryland on Bay matters dates back to 1777.

"This is about cooperative federalism," Herring said, calling the plan to clean up the Bay by 2025 the most promising plan yet to protect and preserve the Bay.

That's not quite the attitude his predecessor had to the EPA.

Ken Cuccinelli represented the Virginia Department of Transportation in a lawsuit challenging the agency's efforts to regulate the volume of stormwater flowing into a Fairfax County stream, arguing that the EPA was treating rainwater itself as a pollutant. A federal judge agreed with the argument.

Material carried by storm runoff, as opposed to the water itself, is one of the items the EPA Chesapeake cleanup plan targets.

Environmental groups praised Herring's move.

"Virginia has long been a full and active Bay restoration partner and was at the table to help craft the (Bay cleanup) blueprint, a federal-state plan that has been called the Bay's best, and perhaps last, chance for restoration," said Will Baker, president of the Chesapeake Bay Foundation. He said the Bay cleanup effort is about half-way done, but that the half that remains will be harder to do.

Emily Francis, interim director of the Virginia League of Conservation Voters, said "if the energy and resource spent on attempts to derail the Bay cleanup plan were instead spent on reducing pollution, we'd be much closer to having a restored Bay."